The present invention relates to inspecting various kinds of objects and, more particularly, to optically inspecting the geometry of such objects.
Various objects prepared for incorporation in corresponding arrangements must often, for those arrangements to have sufficient quality for their intended use or uses, satisfy a variety of criteria to be suitable for those arrangements. Thus, for example, components for machine assemblies frequently have exacting geometrical shape requirements to fit and operate properly in those assemblies. Therefore, the dimensions of such components must be verified prior to assembly to assure both component quality and assembly quality.
However, many kinds of components are of a significant size and have relatively complicated geometrical shapes making the measuring of their various dimensions tedious and prone to repeatability errors as well being slow and expensive. As a result, various kinds of remote sensing arrangements have evolved, often termed close range digital photogrammetry or machine vision metrology, to determine from photographic images the geometrical characteristics of objects subjected to this measurement process. The technology, though, involves many steps in its application including a substantial fraction in which even small variations can vary the results obtained in the process from what they would otherwise be. Thus, there is a desire for a method of optically inspecting objects that provides repeatable and accurate results.